Method of refining mineral oil



Patented Dec. 3, 1940 PATENT oFF-ics METHOD OF REFINING MINERAL OILBoris Malishev, Elizabeth, N. J., assignor of thirty and one-third percent to Universal Development Corporation, New York, N. Y., and threeper cent to John P. Nikonow, New York, N. Y.

No Drawing. Application August 12, 1939, Serial No. 289,919

3 Claims.

As I disclosed in the foregoing and patents,

my catalyst which represents a mixture of a min eral phosphate,superphosphate or Thomas slag with sulfuric acid or its equivalentcalcined at a temperature sufiicient largely to expel free sulfuric acidbut below red heat, can be also used for refining mineral hydrocarbonmixtures or their synthetic equivalents such as are obtained from coalcarbonization, retorting bituminous 2O shales, Berguis, Fisher-Tropshprocesses and others.

Although my process can be used for refining any types of hydrocarbonmixtures, including the less volatile petroleum fractions, such as kero--5 sene and lubricating oils, its most important application is forrefining cracked gasoline.

High octane gasoline obtained by high tem-' perature vapor phasecracking is very difficult to refine. Sulfuric acid, the most commonlyused refining agent, is not suitable for refining this type ofdistillate; it gives treating losses of gasoline sometime as high asfifteen per cent (15%) and a considerable reduction of octane number.Several new refining agents were proposed, but

they were either too expensive, or involved certain difiiculties such asrapid exhaustion, corrosion of equipment, poisonous effect, etc., whichmake practical application of the methods employing such agentsimpractical and sometime 10 even prohibitive.

My catalyst does not possess all these disadvantages and is cheaper thansimilar refining agents, such as phosphorus pentoxide orv solidphosphoric acid catalyst.

My process in practice is carried out by passing hot oils or petroleumvapors through a heated bed of my catalyst. The refining action of mycatalyst on cracked gasoline in most cases starts at 150 C., but is veryslow and incomplete at that temperature. The optimum refiningtemperature lies in the range of 250-300 C. The optimum temperaturesmust be determined by every type of the crude oil. It is not advisableto proceed above 300" 0., because at this temperature the crackingstarts and produces 00 ored distillates; the gum formation alsoincreases with the temperature. The time of contact with the catalystdepends on the difiiculty encountered in effecting refining to thedesired degree and varies from a fraction of a second to one or twominutes. To prevent material vaporization and drying out of thecatalyst, sufficient superheated steam must be introduced into thecatalytic chamber together with the crude gasoline. The amount of steamdetermined as water must be about twenty per cent (20%) of the liquidgasoline.

Gum deposits rather rapidly if the distillate is totally in the vaporstate. Hot liquid mineral oils dissolve the gum and prevent itsdeposition on the catalyst. For'that reason, in order to secure a goodgum, free contact with the catalyst and prolong its life, I prefer touse medium pressures, such that a mixture of gas and liquid is formed.The pressure of about 200 pounds per square inch is sufficient for thispurpose. The treating losses with my catalyst are very small and are ofan order of about 1.0% on cracked distillate. These losses are dueexclusively to polymerization to high boiling fractions.

EmampZa-A cracked unrefined gasoline of yellow color, poor inductionperiod (two hours) and high copper disc gum content (600 mg. per cc.)was pumped through a bed of my catalyst at 225 C. and at 200 poundspressure with twenty per cent (20%) steam. The product was redistilledto the desired end point.

The gasoline thus refined had a Saybolt color of 30+, copper disc gum of10 mg. per100 cc., and an induction period of ten hours. The antiknockrating rose from 67 to 70 octanes. treating losses were about 1.0%. Thelife of the catalyst was 200 gallons gasoline per one pound of catalyst.

I claim as my invention:

1. A method of refining cracked gasoline, consisting in treatinggasoline with a catalyst consisting of a solid calcined product of amixture of a subtsance taken from the group consisting of a mineralphosphate, superphosphate and Thomas slag, with sulfuric acid, thetreatment being conducted at a temperature from about to 300 C. and at apressure sunlcient to maintain the liquid state.

2. A method of refining cracked gasoline, consisting in treatinggasoline with a catalyst consisting of a solid product of a mixture of asubstance taken from the group consisting of a mineral phosphate,superphosphate and Thomas slag,

with sulfuric acid, calcined at a temperature sufii- The stance takenfrom the group consisting of a mineral phosphate, superphosphate andThomas slag, With sulfuric acid, calcined into a solid product, thetreatment being conducted at an increased temperature but below crackingtemperature and 5 at a pressure suflicient to maintain the liquid state.v BORIS MALISHEV,

